Questions tagged [quantum-chemistry]
Quantum chemistry is a subfield of quantum mechanics. Like its parent field, quantum chemistry focuses on understanding physical phenomena occuring at the atomic scale. Quantum chemistry however is more focused on providing useful descriptions of electronic structure to aid in understanding chemical problems (e.g. reactions, spectra, dynamics, ...).
1,571
questions
3
votes
0
answers
44
views
Integrating out spin in 2-electron energy function
I am just starting to learn Quantum Chemistry for my research. I am currently reading Modern Quantum Chemistry by Szabo and I am a little confused by a concept. The two-electron ground state energy is:...
- 31
2
votes
2
answers
110
views
Why aren't there different peaks for different IE in PhotoElectron Spectroscopy (PES)?
The way I understand PES is that you shine a light on a bunch of atoms and measure the kinetic energy of photons to determine ionisation energies (or energies of electrons... is that different?).
I ...
- 41
2
votes
1
answer
57
views
Frequency to induce nitrogen inversion
I would like to know how to compute the frequency at which nitrogen inversion happens in ammonia gas at STP. The activation energy for such process is 24.2 kJ/mol, therefore I thought that it is ...
- 41
-1
votes
1
answer
80
views
Degeneracy of Orbitals
(Sorry, in advance if my question is silly or low quality but I want to ask this to someone.)
When an electron enters an orbital, it should technically have an electric Field and also magnetic field(...
- 107
1
vote
3
answers
125
views
Challenging Orbital Restrictions
According to the n-l-1 formula for nodal count, wouldn't 1p, 1d, and 1f orbitals be possible since l (angular momentum quantum number) can be 1, 2, and 3 respectively for a principal quantum number (n)...
user145559
0
votes
0
answers
46
views
Why aren't other elements with valence 6s electrons liquid like mercury?
I found out that mercury's 6s electrons undergo relativistic effects that make their pull to the nucleus greater, which makes it so that they can't bond with other atoms of mercury to form a solid. ...
-4
votes
1
answer
78
views
Stability of atomic/ionic quantum states in relation to the full octet rule
We have started our Chemistry Unit and the very first statement the teacher says is that
"All Atoms want to be stable. They achieve this by having a full valence shell, which they achieve by ...
- 1
1
vote
1
answer
168
views
Wave function in Schrodinger's model
I am trying to wrap my head around the Schrodinger's quantum mechanical model of an atom.
According to the NCERT$^1$, the Schrodinger's equation is given by:
$$\hat{H}\Psi=E\Psi$$ where $\hat{H}$ is ...
- 828
1
vote
0
answers
38
views
Resonance stabilization : lowering of kinetic energy or electron repulsion?
Resonance stabilization, or delocalization stabilization, occurs when the overall energy of the molecule is lowered compared the localized "resonance structures".
In solid state physics, or ...
4
votes
0
answers
100
views
The sign of the lobes in an atomic orbital
In atomic orbital diagram of an atomic orbital, the lobes are represented as either positive or negative. It is said that the wave function is 'positive' where the lobe is depicted positive and '...
- 77
1
vote
0
answers
36
views
How to find the global minima of a supramolecular complex in computational chemistry?
So this is more of a complex problem, and my masters thesis could greatly benefit if I find an answer to this.
Essentially, I have a supramolecular inclusion complex. There is this molecule A (the ...
- 11
1
vote
1
answer
92
views
Does ionisation change the physical/chemical properties of an atom?
From what I have learned, the number of electrons on the outermost shell (called the valence electrons), determines the chemical properties of an atom, this is why elements in the same group have ...
- 35
0
votes
0
answers
38
views
What are some general chemistry textbook with good problems? [duplicate]
I’m currently in a General Chemistry course and am wondering if you guys can recommend me a textbook or resource where I can find good problems to work through and further my understanding. We’re ...
- 11
0
votes
0
answers
41
views
How does more s character shorten bonds and strengthen bonds?
I'm aware that having more s character means that electrons are in the lowest energy state (?) and very close to the positive atomic nucleus. But then what’s the connection between having electrons ...
- 11
5
votes
0
answers
157
views
N2 HOMO-LUMO Gap calculation
I am thinking about calculating the HOMO-LUMO energy gap for $\ce{N2}$ molecule.
I thought I could model this as a particle in a box problem to find $E_\text{HOMO}$ and $E_\text{LUMO}$.
The formula I ...
- 151